ActionConfirm the message was valid and should be confirmed.

ActionReject the message was successfully processed, but was malformed/invalid and should be marked as rejected.

ActionRetry a recoverable error was encountered - batch should be halted and then re-processed from the start.

ActionWait the message is still awaiting further pieces for aggregation and should be held in pending state.

DefinitionBatchState tracks the state between definition handlers that run in-line on the pin processing route in the aggregator as part of a batch of pins.

DefinitionHandlers interface allows components to call broadcast/private messaging functions internally (without import cycles).

DefinitionMessageAction is the action to be taken on an individual definition message.